Background: Electronic apex locators can be a useful adjunct with a high level of accuracy for determining the real root canal length in clinical practice. Aim: The objective of this ex vivo study was to evaluate the accuracy of electronic apex locator for real working length determination in comparison with a manual method. MaterialsandMethods: Forty single-rooted teeth were used in this study. After coronal access, manual measurement of the real working length of each root canal was performed by placing a size 10 K-file, using as reference the exceeding of the file in the apical foramen. The file was retracted by 1 mm, and its extension was measured to determine the real working length. The electronic measurement of the working length was performed in the same teeth using the Joypex 5 electronic apex locator. Results: Data were submitted to statistical analysis (Wilcoxon-Mann-Whitney test, P > 0.05) and no significant difference was found between the electronic and manual methods (P > 0.05). Conclusions: It may be concluded that the electronic apex locator is a reliable and accurate method for determining the working length of root canals, optimizing the odontometric procedure in clinical practice.